Specifies what content encodings have been applied to the object and thus
what decoding mechanisms must be applied to obtain the media-type referenced
by the Content-Type header field.
If the object expiration is configured (see PUT Bucket lifecycle), the
response includes this header. It includes the expiry-date and rule-id
key-value pairs providing object expiration information. The value of the
rule-id is URL encoded.
This is set to the number of metadata entries not returned in
x-amz-meta headers. This can happen if you create metadata
using an API like SOAP that supports more flexible metadata than the REST
API. For example, using SOAP, you can create metadata whose values are not
legal HTTP headers.
If server-side encryption with a customer-provided encryption key was
requested, the response will include this header confirming the encryption
algorithm used.
If server-side encryption with a customer-provided encryption key was
requested, the response will include this header to provide round-trip
message integrity verification of the customer-provided encryption key.
If present, specifies the ID of the AWS Key Management Service (AWS KMS)
symmetric customer managed customer master key (CMK) that was used for the
object.
If the bucket is configured as a website, redirects requests for this object
to another object in the same bucket or to an external URL. Amazon S3 stores
the value of this header in the object metadata.